ObjectivesAt the end of the lecture, the student should be able to: Define the arterial system. List major arteries and their distribution in the neck. Define the venous system. List major veins and their distribution in the neck.
General principles of arterial supply Arteries carry blood away from the heart. All arteries, carry oxygenated blood except the pulmonary and umbilical arteries, which carry deoxygenated blood to the lungs (postnatal) and to the placenta (prenatal) respectively The flow of blood depends on the pumping action of the heart. There are no valves in the arteries. The branches of arteries supplying adjacent areas normally anastomose with one another freely providing backup routes for blood to flow if one link is blocked.
Aorta (FYI) It is the largest artery in the body. Originates from the left ventricle. It is divided into 4 parts. It carries oxygenated blood to all parts of the body.
Arch of Aorta (FYI)Branches of Arch of Aorta1. Left Subclavian artery.2. Left Common Carotid artery.3. Brachiocephalic trunk.
Common Carotid Artery Common Carotid Arteries supply Head &Neck. Left common carotid arises from aorticarch. Right common carotid arises fromBrachiocephalic trunk. Each artery runs upward, embedded intothe carotid sheath through the neck, fromthe sternoclavicular joint to the upper borderof the thyroid cartilage. Each common carotid gives two branches: Internal carotid External carotid
Common Carotid ArteryRelations Antrolaterally Skin, fascia Sterocledomastoid Sternohyoid Sternothyroid Superior belly of omohyoid Posteriorly Transverse process of the lower 4 cervical vertebrae Prevertebral muscles Sympathetic trunk Vertebral vessels
Common Carotid ArteryRelations Medially Larynx pharynx, Trachea esophagus Lobe of thyroid gland Laterally Internal jugular vein Vagus nerve
External Carotid Artery It divides behind neck of the mandibleinto two 2 terminal branches: Superficial temporal Maxillary artery It supplies: Scalp: Superficial temporal artery Face: Facial artery Maxilla: Maxillary artery Tongue: Lingual artery Glands: Superior thyroid artery
Superior Thyroid Artery Arises from the external carotid artery just below the hyoid bone. Ends in the thyroid gland. Supplies thyroid gland.
Ascending Pharyngeal Artery The smallest branch of the external carotid. Deeply seated in the neck, beneath the other branches of the external carotid. It lies just superior to the bifurcation of the common carotid artery. Supplies pharynx.
Internal Carotid Artery Has no branches in the neck andenters the cranial cavity. Supplies structures inside skull. Arises from the common carotid atthe level of the superior border of thethyroid cartilage It is embedded in the carotid sheathwith internal jugular vein and vagusnerve . It Supplies: Brain Nose Scalp Eye
Subclavian Artery Left subclavian arises from aorticArch. Right subclavian arises frombrachiocephalic trunk. Subclavian arteries give contributionto CNS through one of its mainbranches; Vertebral artery. Supply CNS
General principles of Venous Drainage Veins are blood vessels that bring blood back to the heart. All veins carry deoxygenated blood with the exception of the pulmonary veins and umbilical veins There are two types of veins: Superficial veins: close to the surface of the body NO corresponding arteries Deep veins: found deeper in the body With corresponding arteries
Veins of Neck Two divisions: Superficial Veins External Jugular veins Anterior jugular veins Deep Veins Internal Jugulars veins
Superficial Veins of Neck External Jugular veins: Lies superficial to the sternomastoid muscle It passes down the neck and it is the only tributary of the subclavian vein. It drains blood from: Outside of the skull Deep parts of the face
Superficial Veins of Neck Anterior jugular veins: It begins in the upper part of the neck by the union of the submental veins. It descends close to the median line of the neck, medial to the sternomastoid muscle. At the lower part of the neck, it passes laterally beneath that muscle to drain into the external jugular vein. Just above the sternum the two anterior jugular veins communicate by a transverse vein to form the jugular arch. Receives drainage thyroid and pharynx.
Superficial Veins of NeckInternal Jugulars vein: Drains blood from the head, brain, face & neck. It descends in the neck along with the internal and common carotid arteries and vagus nerve, within the carotid sheath. Joins the subclavian vein to form the brachiocephalic vein. Tributaries: Superior thyroid Lingual Facial Occipital veins Dural venous sinuses
Superior Vena Cava Formed by the union of the rightand left brachiocephalic veins. Brachiocephalic veins are formedby the union of internal jugular andsubclavian veins. Drains venous blood from: Head, neck, thoracic wall & upper limbs It Passes downward and enter the right atrium.